Field of the Invention
The present invention relates to a wired circuit board and a producing method thereof, to be specific, to a wired circuit board preferably used as a suspension board with circuit and a producing method thereof.
Description of Related Art
In a wired circuit board used in an electronic and electrical device or the like, a terminal portion for being connected to an external board is usually formed.
To correspond to high density and miniaturization of the electronic and electrical device, a flying lead in which a terminal portion is formed not only on one surface of a conductor pattern, but also on both surfaces thereof has been recently spread. For example, in a suspension board with circuit or the like to be used in a hard disk drive, it has been known that the terminal portion is formed as the flying lead by disposing the terminal portion so that both surfaces thereof are exposed in an opening formed in a supporting board and an insulating layer.
A plating layer is formed on both surfaces of the thus exposed flying lead by electrolytic plating.
Meanwhile, the terminal portion formed as the flying lead has low rigidity, so that there may be a case where defects such as a sag or a bend occur in the flying lead by impact or vibration on the suspension board with circuit. Then, a suspension board with circuit that is capable of suppressing a sag or a bend of a flying lead by forming a reinforcement supporting portion by leaving a part of a supporting board between a plurality of flying leads at the time of trimming of the supporting board has been proposed (ref: for example, Japanese Unexamined Patent Publication No. 2014-123711).